A few interesting whitepapers comparing SQL Server 2005 to Oracle (and particularly the use of RAC) have just been posted here http://www.microsoft.com/sql/prodinfo/compare/oracle/default.mspx.
On a slightly different note (non-SQL Server), I am disappointed that PDF support is being pulled from Office 2007. I've been using this a lot in Beta 2 however I hear it might be included as a free download but not sure yet. Brian has a good post about the reasons for removing PDF support http://blogs.msdn.com/brian_jones/archive/2006/06/02/613702.aspx. This is Adobe's official response http://www.adobe.com/aboutadobe/pressroom/statement.html